<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>提示</title>
</head>
<body>
    <div class="warntext">
        请升级你的浏览器!
    </div>
</body>
<style>
    .warntext{
        position: fixed;
        top: 30%;
        left: 50%;
        width: fit-content;
        padding: 50px;
        margin-left: -114px;
    }
</style>
</html>